1. Field of the Invention
The invention relates to a method for showing an array microphone effect, and more particularly to a method for visualizing an original acoustic signal obtained by array microphones, enabling the user to know what sounds the array microphones are picking up at any time.
2. Description of the Related Art
A microphone array is capable of clearly receiving sound from a particular direction while avoiding noise and/or echo, and is often applied in high-quality audio recorders or communications devices.
There are different types of microphone arrays. For example, a broadband microphone array includes two omni-directional microphones that simultaneously receive sound, thereby forming a pie beam, wherein a designated signal within the beam is received, and noise outside of the beam is suppressed. For another example, a SAM (small array microphone) includes a uni-directional microphone and an omni-directional microphone that simultaneously receive sound, thereby forming a cone beam, wherein a designated signal within the beam is received. Alternatively, a SAM includes two omni-directional microphones that simultaneously receive sound, thereby forming a pie beam or a cone beam, wherein a designated signal within the beam is received.
FIG. 1A depicts an example of a pie beam 130 which is defined in front of and at the rear of a microphone array 110. As shown, a notebook computer is provided with the microphone array 110 on the top and connected to two loudspeakers 120 on both sides, thus allowing a user to communicate with other people at a far end through an internet. Original acoustic signals picked up by the array microphones 110 include a crystal voice (the user's voice within a pie beam 130), echo, background noise, and out-beam noise. The original acoustic signals are then processed by hardware (e.g. IC chip) or software, wherein the echo is canceled, the background noise and out-beam noise are suppressed, and the crystal voice is sent to the far-end talker through the internet. Also, the far-end talker's voice is output from the loudspeakers 120.
FIG. 1B depicts an example of a cone beam 130′ which is defined in front of a microphone array 110′. As shown, a notebook computer is provided with the microphone array 110′ on the top and connected to two loudspeakers 120′ disposed on a side, thus allowing a user to communicate with other people at a far end through an internet. Similarly, original acoustic signals picked up by the array microphones 110′ include a crystal voice (user's voice in a cone beam 130′), echo, background noise, and out-beam noise. The original acoustic signals are then processed by hardware or software, wherein the echo is canceled, the background noise and out-beam noise are suppressed, and the crystal voice is sent to the far-end talker through the internet Also, the far-end talker's voice is output from the loudspeakers 120′.